1. Field of the Invention
This invention relates to push-button type writing instruments making use of evaporative or volatile ink, such as felt pens, ball-point pens with water-base ink, etc.
2. Description of the Prior Art
A variety of push-button type structures has heretofore been proposed for writing instruments making use of evaporative or volatile ink, such as felt pens, ball-point pens with water-base ink, etc. Such conventional structures were all accompanied by such drawbacks so that their air tightness were poor and inks tended to evaporate off or they did not permit smooth core-projecting operations.